AgCNi electric contact material, preparation method and electric contact

Abstract

The invention provides an AgCNi electric contact material, a preparation method and an electric contact, and the preparation method comprises the steps: mixing silver powder, nickel powder and graphite powder according to a preset proportion to obtain mixed powder; performing isostatic pressing treatment to obtain an AgCNi spindle; sintering is conducted, and an AgCNi billet is obtained; the AgCNi billet is extruded according to the preset deformation amount, and an AgCNi wire or strip is obtained; carrying out decarburization treatment to form an AgCNi wire or strip with four side walls made of AgNiO; and performing reduction treatment to obtain an AgCNi wire or strip with four surfaces being AgNi, namely the AgCNi electric contact material. According to the method, through the process of combining extrusion, decarburization and reduction, secondary homogenization of the internal structure of the material is achieved, the compactness of the structure of the AgCNi material is greatly improved, and therefore the arc ablation resistance of the AgCNi material is improved, and the service life of the AgCNi material is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of electric contact materials, and in particular to an AgCNi electric contact material and a preparation method and an electric contact. Background Art

[0002] Silver-nickel graphite (AgCNi) electrical contact material is widely used in switchgear such as molded case circuit breakers and frame circuit breakers because of its good resistance to welding and low and stable contact resistance.

[0003] Existing manufacturers mainly use the pressing-sintering method to prepare AgCNi electrical contact materials. The process usually includes: batching-powder mixing-ball milling-granulation-pressing (i.e., first adding AgCNi powder, and then adding pure Ag powder as a composite layer)-sintering-compression-cleaning-heat treatment process, but the product obtained by this method has extremely poor density and uneven material structure, resulting in poor wear resistance and arc ablation resistance of the product, which seriously affects the electrical life of the product and may even cause fire in severe cases. In addition, due to the poor wettability of graphite with silver and copper, it is easy to form a cold weld when the AgCNi material is welded with the copper contact bridge, thereby affecting the reliability and service life of the switch electrical appliance. Some technicians add a layer of pure silver or silver-nickel material on the surface of the AgCNi material by compounding or spreading powder to solve the problem of weak welding between the AgCNi electrical contact material and the copper contact bridge, but when the C content exceeds 3%, the composite interface of AgCNi and pure silver is prone to blistering or stratification.

[0004] There are few studies on AgCNi electrical contact materials and their preparation methods at home and abroad. Patent CN 113245547 A obtains a silver-nickel graphite electrical contact material with a continuous decarburized layer on the side and an arbitrary structure through powder mixing-initial pressing-sintering-recompression-decarburization-cutting or milling-cleaning-annealing. Although this method solves the problem of blistering or stratification at the interface between AgCNi and pure silver, the powder used is spherical and there are pores between the particles. Due to the pressure of the molding method, these pores cannot be completely eliminated, so there are still problems such as poor density, low bonding strength between the reinforcing phase graphite and the silver matrix, and uneven material structure, resulting in poor arc ablation resistance and short life of the product.

[0005] Patent CN 102808098 A uses chemical plating and extrusion to obtain silver-nickel graphite electrical contact materials, which helps to improve the densification of the material structure, the wettability of the enhanced phase and the silver matrix, and the ablation resistance. However, this method uses chemical plating, which takes a lot of time to obtain a sufficient batch of nickel-coated graphite, making it difficult to achieve mass production.

[0006] Therefore, there is an urgent need to develop an AgCNi electrical contact material and a preparation method thereof to solve at least one of the above problems. Summary of the invention

[0007] In view of the defects in the prior art, an object of the present invention is to provide an AgCNi electrical contact material and a preparation method and an electrical contact.

[0008] According to a first aspect of the present invention, there is provided a method for preparing an AgCNi electrical contact material, comprising:

[0009] Mixing silver powder, nickel powder and graphite powder according to a preset ratio to obtain a mixed powder;

[0010] The mixed powder is subjected to isostatic pressing to obtain an AgCNi ingot;

[0011] Sintering the AgCNi ingot to obtain an AgCNi ingot;

[0012] Extruding the AgCNi billet according to a preset deformation amount to obtain an AgCNi wire or strip;

[0013] Decarburizing the AgCNi wire or strip to form an AgCNi wire or strip with four side walls all made of AgNiO;

[0014] The decarburized AgCNi wire or strip is subjected to reduction treatment to obtain an AgCNi wire or strip with AgNi on four surfaces, namely, an AgCNi electrical contact material.

[0015] Optionally, the mixed powder is subjected to isostatic pressing to obtain an AgCNi ingot, wherein: the pressure is 50 MPa to 400 MPa, and the time is 10 seconds to 120 seconds.

[0016] Optionally, the sintering of the AgCNi ingot to obtain an AgCNi billet comprises:

[0017] First, the AgCNi ingot is loaded into a sintering furnace and preheated in a protective atmosphere at a temperature of 200° C. to 500° C. for a preheating time of 0.1 hour to 3 hours;

[0018] Then, the preheated AgCNi ingot is subjected to a second-stage sintering in a protective atmosphere, the sintering temperature is 350° C. to 650° C., and the sintering time is 0.5 hour to 5 hours;

[0019] The third stage sintering is then carried out under a protective atmosphere, with a sintering temperature of 700°C to 950°C and a sintering time of 0.5 hour to 10 hours, and then the product is cooled to room temperature and taken out of the furnace.

[0020] Optionally, the AgCNi billet is extruded according to a preset deformation amount, wherein the preset deformation amount includes: an extrusion ratio of 20-300.

[0021] Optionally, the AgCNi ingot is extruded according to a preset deformation amount to obtain an AgCNi wire or strip, wherein: a hot extrusion method is adopted, the hot extrusion temperature is 500° C. to 900° C., and the extrusion time is 0.5 hour to 4 hours.

[0022] Optionally, the AgCNi wire or strip is subjected to a decarburization treatment to form an AgCNi wire or strip having four side walls of AgNiO, wherein: the decarburization temperature is 600° C. to 850° C., and the gas flow rate is 5 to 20 L / min.

[0023] Optionally, the decarburized AgCNi wire or strip is subjected to reduction treatment to obtain an AgCNi wire or strip having AgNi on all four surfaces, wherein: the reduction temperature is 400° C. to 800° C., and the reduction time is 0.5 hour to 6 hours.

[0024] Optionally, before subjecting the mixed powder to isostatic pressing to obtain the AgCNi ingot, the process includes: subjecting the mixed powder to ball milling.

[0025] According to a second aspect of the present invention, there is provided an AgCNi electrical contact material, which is prepared using the above method.

[0026] According to a third aspect of the present invention, there is provided an electrical contact, which is prepared using the above-mentioned AgCNi electrical contact material, by cutting the AgCNi electrical contact material into slices to obtain AgCNi particles whose four surfaces are all AgNi; the AgNi layer on one side of the AgCNi particle is milled off to obtain a single-piece AgCNi electrical contact.

[0027] Compared with the prior art, the present invention has at least one of the following beneficial effects:

[0028] 1. The present invention realizes secondary homogenization of the internal organization of the material through a process combining extrusion, decarburization and reduction, greatly improves the compactness of the AgCNi material organization, thereby improving the arc ablation resistance and service life of the AgCNi material, and effectively solves the problems of low organization density, poor ablation resistance and short electrical life of the existing AgCNi electrical contact material by molding. The internal organizational structure of the AgCNi material is oriented in a fibrous manner along the extrusion direction, and its arc resistance is better than that of conventional products. In addition, the AgCNi wire is first decarburized and then reduced to remove the C element on the surface of the wire while retaining Ag and Ni, and an AgNi welding layer is formed in situ, without the need for a composite silver layer, thereby avoiding the problems of blistering and stratification caused by the composite process, and improving the yield rate of the product; and AgNi is a very good welding material, so that the composite interface of the matrix and the welding layer is firmly combined, and the AgCNi product can be well welded with the copper part, avoiding the situation that the silver matrix falls off from the composite interface of the welding layer during the electrical life, and the welding with the copper part is not strong, etc., effectively improving the use performance of the AgCNi material. The preparation method of the invention is simple to operate and easy to mass produce, which is beneficial to improving the yield rate of the product.

[0029] 2. Among the four side walls of the AgCNi material prepared by the present invention, two side walls are made of AgNi and the other two side walls are made of AgCNi, which can effectively avoid the problem of forming a continuous decarburization layer around, and is conducive to improving the anti-welding performance of the AgCNi electrical contact. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0031] Figure 1 Schematic diagram of the process of preparing AgCNi electrical contact material in one embodiment of the present invention.

[0032] Figure 2 This is a schematic diagram of the structure of AgCNi wire after reduction in one embodiment of the present invention;

[0033] Figure 3 This is a schematic diagram of the structure of the AgCNi wire after cutting in one embodiment of the present invention;

[0034] Figure 4 It is a schematic structural diagram of a single-piece AgCNi electrical contact with one side of the AgNi layer milled off in one embodiment of the present invention;

[0035] In the figure, 1 is AgCNi material, and 2 is AgNi layer. DETAILED DESCRIPTION

[0036] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several variations and improvements may be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0037] Reference Figure 1 As shown, a method for preparing an AgCNi electrical contact material provided by an embodiment of the present invention comprises the following steps:

[0038] S1. Powder mixing: silver powder, nickel powder and graphite powder are mixed according to a preset ratio to obtain a mixed powder;

[0039] S2, isostatic pressing: isostatically pressing the mixed powder to obtain an AgCNi ingot;

[0040] S3, sintering: sintering the AgCNi ingot to obtain an AgCNi ingot;

[0041] S4, extrusion: extruding the AgCNi billet according to a preset deformation amount to obtain an AgCNi wire or strip;

[0042] S5, decarburization: decarburizing the AgCNi wire or strip to form an AgCNi wire or strip with four side walls being AgNiO;

[0043] S6. Reduction: The decarburized AgCNi wire or strip is subjected to reduction treatment to obtain an AgCNi wire or strip having AgNi on all four surfaces, namely, an AgCNi electrical contact material.

[0044] In step S1, the mass percentage of each powder is: nickel is 1.0% to 30.0%, graphite is 0.5% to 5.0%, and the balance is silver. The function of the nickel element is mainly to increase the material strength and improve the material electrical life; the function of the graphite element is mainly to improve the material's resistance to fusion welding. When the graphite exceeds 5%, the material plasticity is very poor and it is difficult to achieve extrusion.

[0045] Silver powder, nickel powder and graphite powder are placed in a powder mixer according to a preset ratio and mixed for 1 to 20 hours. The powder dispersibility is improved through the powder mixing steps and parameter settings to ensure that the powders are mixed evenly.

[0046] To form a dense billet without chipped corners, in some embodiments, in step S2, the isostatic pressing pressure is 50 MPa to 400 MPa, and the time is 10 seconds to 120 seconds.

[0047] In some embodiments, in step S3, the AgCNi ingot is first loaded into a sintering furnace and preheated under a protective atmosphere at a temperature of 200°C to 500°C for a preheating time of 0.1 to 3 hours; through the first stage sintering, a portion of the pores in the particles and the billet are removed; then the preheated AgCNi ingot is subjected to a second stage sintering under a protective atmosphere at a temperature of 350°C to 650°C for a sintering time of 0.5 to 5 hours; through the second stage sintering, a neck connection is formed between the powders; then the third stage sintering is carried out under a protective atmosphere at a temperature of 700°C to 950°C for a sintering time of 0.5 to 10 hours, and through the third stage sintering, the pores are reduced and shrunk, the lattice distortion is reduced, and the density and conductivity of the material are improved; and then the material is cooled to room temperature and taken out of the furnace.

[0048] Exemplarily, the protective atmosphere may be any one of hydrogen, argon, nitrogen and nitrogen-hydrogen mixed gas to protect the AgCNi ingot from oxidation during the sintering process.

[0049] In some embodiments, the AgCNi billet is extruded according to a preset deformation amount, wherein the preset deformation amount includes: an extrusion ratio of 20-300.

[0050] Specifically, in step S4, the sintered AgCNi billet is placed in an 1100T extruder by hot extrusion, and large deformation extrusion is performed under a protective atmosphere to obtain AgCNi wire or strip. The hot extrusion temperature is 500°C to 900°C, and the extrusion time is 0.5 hours to 4 hours. The decarburization time can be conventionally adjusted according to the thickness of the final product and the thickness of the silver layer. By setting the various parameters of the extrusion process, extrusion is equivalent to pressurizing the material from multiple directions, so that the material density far exceeds the conventional powder pressing method product and is more resistant to arc ablation.

[0051] In the above-mentioned embodiment of the present invention, a large extrusion ratio is used for extrusion, and the internal material will flow along the extrusion direction and drive the internal reinforcement phase particles to present an orderly distribution, that is, present a directional fiber tissue state.

[0052] In some embodiments, in step S5, the AgCNi wire or strip is placed in a decarburization furnace, oxygen or compressed air is introduced for decarburization, the C on the surface of the AgCNi is oxidized into gaseous CO, CO2, and the surface Ni is oxidized into NiO. After a period of decarburization and oxidation, a certain depth of AgNiO layer will be formed on the surface of the wire, thereby obtaining AgCNi wire or strip with AgNiO on all four surfaces. The decarburization temperature is 600°C to 850°C, and the gas flow rate is 5 to 20L / min. The decarburization time can be conventionally adjusted according to the thickness of the final product and the thickness of the silver layer. By setting the various parameters of the decarburization process, the AgNiO decarburization layer on all surfaces of the AgCNi wire or strip reaches the required thickness, preparing for the subsequent in-situ formation of a good welding layer.

[0053] In some embodiments, in step S6, the decarburized AgCNi wire or strip is placed in a sintering furnace, hydrogen is introduced, and reduction treatment is performed at high temperature, so that NiO on the surface of the wire is reduced to Ni, and AgCNi wire or strip with AgNi on all four surfaces is obtained. The reduction temperature is 400°C to 800°C, and the reduction time is 0.5 hours to 6 hours. By setting the parameters of the reduction process, the AgNiO decarburized layers on all surfaces of the AgCNi wire or strip are all in-situ reduced to AgNi welding layers, such as Figure 2 As shown, the AgNi layer 2 is formed on the four surfaces of the AgCNi material 1 .

[0054] The above-mentioned embodiment of the present invention adopts a method of large deformation extrusion combined with decarburization and reduction to improve the compactness of the AgNiC material structure, making the material more resistant to arc erosion and having a longer service life; at the same time, the present invention adopts large deformation extrusion to redistribute the material structure, break the interface of the original particles, achieve secondary homogenization of the internal structure, and improve the electrical properties of the material. The above-mentioned embodiment of the present invention generates an AgNi welding layer in situ through decarburization and reduction, without the need for a composite silver layer, thereby avoiding problems such as the substrate falling off from the composite layer and poor welding with copper parts, thereby improving the product's performance and yield rate. The method in the above-mentioned embodiment of the present invention can be used to obtain AgCNi electrical contact materials with high resistance to fusion welding, long service life, and easy batch production, which are simple to operate and easy to batch produce.

[0055] In some embodiments, before the mixed powder is subjected to isostatic pressing to obtain the AgCNi ingot, the process includes: ball milling the mixed powder. Specifically, wet high-energy ball milling the mixed powder, and then drying. The mixed powder and the liquid medium are placed in a high-energy ball mill, filled with inert gas, and then wet high-energy ball milling is performed, and then dried and sieved after completion. Among them, the ball milling process parameters are: the ball-to-material ratio is 1 to 20, the rotation speed is 100 rpm to 600 rpm, and the ball milling time is 2 hours to 30 hours. Through the high-energy ball milling step and the setting of each parameter, the mixed powder is refined under high-energy collision and rolling to form a uniform and ultra-fine composite powder coated with ultra-fine silver particles or nickel particles on the outside, thereby improving the surface activity of the powder, and then improving the bonding strength between the reinforcing phase and the silver matrix. The drying process parameters are: the drying temperature is 50°C to 150°C, and the drying time is 2 hours to 20 hours to remove the liquid medium in the powder after ball milling.

[0056] The above-mentioned embodiment of the present invention improves the wettability of the reinforcing phase graphite and the silver matrix by combining high-energy ball milling with extrusion, and increases the bonding strength between the reinforcing phase and the silver matrix, thereby improving the arc erosion resistance of the product.

[0057] The above-mentioned embodiment of the present invention selects a large deformation extrusion method and a high-energy ball milling, decarburization and reduction process in combination according to the application of AgCNi materials in low-voltage electrical appliances such as frame circuit breakers, thereby improving the welding resistance and arc erosion resistance of the AgCNi material, thereby increasing the service life of the AgCNi material.

[0058] Based on the same concept, an embodiment of the present invention provides an AgCNi electrical contact material, which is prepared using the above method. The AgCNi electrical contact material has a microstructure with orderly distribution of the reinforcement phase, the welding layer and the two side walls are made of AgNi, and the other surface materials are AgCNi.

[0059] Based on the same concept, another embodiment of the present invention is an electrical contact, which is prepared by using the above-mentioned AgCNi electrical contact material. The electrical contact can be obtained by cutting and milling. The cutting step includes cutting the AgCNi electrical contact material into pieces to obtain AgCNi particles with four surfaces being AgNi, such as Figure 3 As shown, after cutting the wire or strip along the length direction, a plurality of sheet materials are obtained, and the four surfaces of the AgCNi material 1 are all AgNi layers 2; the milling step includes milling off one side of the AgNi layer of the AgCNi particles to obtain a single AgCNi electrical contact, such as Figure 4 As shown, among the four side walls of the AgCNi material 1, two side walls are AgNi layers 2, and the other two side walls are made of AgCNi, which can effectively avoid the problem of forming a continuous decarburized layer around, and is conducive to improving the anti-welding performance of the AgCNi electrical contact.

[0060] Furthermore, the AgCNi electrical contact is ground and polished, and then dried, and the finished AgCNi electrical contact material is obtained through the above cleaning and drying process.

[0061] Continue to refer to Figure 1 In a specific embodiment, a method for preparing a AgC3Ni30 electrical contact material comprises the following steps:

[0062] Step 1: Place silver powder, nickel powder and graphite powder in a powder mixer according to a preset ratio and mix for 4 hours; wherein the weight proportions of various powders are: graphite powder: 3.0%, Ni powder: 30%, and the remainder is Ag powder to obtain a mixed powder.

[0063] Step 2: Put the sieved mixed powder and alcohol into a horizontal ball mill for wet high-energy ball milling, wherein the ball-to-material ratio is 5, the ball-milling speed is 260 rpm, and the ball-milling time is 5 hours; then place the ball-milled material in an oven, introduce argon inert gas protection, and carry out drying treatment, and the drying process parameters are: drying temperature is 80°C, and drying time is 3 hours.

[0064] Step 3: The ball-milled powder is isostatically pressed at a pressure of 350 MPa for 100 seconds to obtain an AgCNi ingot.

[0065] Step 4: After the AgCNi ingot is loaded into the sintering furnace, it is preheated in a nitrogen-hydrogen mixed gas atmosphere at a temperature of 300°C for 1.5 hours; then the preheated ingot is subjected to a second-stage sintering in a H2 atmosphere at a sintering temperature of 600°C for 3 hours; then the third-stage sintering is carried out in a H2 atmosphere at a sintering temperature of 830°C for 6 hours, and then cooled to room temperature and taken out of the furnace to obtain an AgCNi ingot.

[0066] Step 5: Place the sintered AgCNi billet in a 1100T extruder and perform large deformation extrusion under N2 protective atmosphere to obtain AgCNi wire with orderly arrangement of reinforcement phase. The hot extrusion temperature is 800℃, the extrusion ratio is 200, and the extrusion time is 1.0 hour. The preheating temperature of the extrusion die is 350℃.

[0067] Step 6: Place the AgCNi wire in a decarburization furnace, introduce oxygen for decarburization, oxidize the C on the AgCNi surface into gaseous CO and CO2, and oxidize the Ni on the surface into NiO, and obtain AgCNi wire with AgNiO on all four surfaces. The decarburization temperature is 780°C, the gas flow rate is 15L / min, and the decarburization time is 6 hours.

[0068] Step 7: Place the decarburized AgCNi wire in a sintering furnace, introduce H2 gas, and perform high-temperature reduction treatment, so that NiO on the surface of the wire is reduced to Ni, and obtain an AgCNi wire with AgNi on all four surfaces. The reduction temperature is 500°C and the reduction time is 4 hours.

[0069] Step 8: Cut the reduced AgCNi wire into pieces to obtain AgC3Ni30 particles with AgNi on all four surfaces.

[0070] Step 9: Mill off one side of the AgNi layer of the AgC3Ni30 particles to obtain a single AgC3Ni30 electrical contact.

[0071] Step 10: Grind and polish the AgC3Ni30 electrical contact obtained in S9, and then dry it to obtain a finished AgC3Ni30 electrical contact material with two side surfaces being AgNi, two side surfaces being AgCNi, and a welding surface being AgNi.

[0072] The AgCNi electrical contacts prepared by the molding method were used as a comparison, and the performance of the two electrical contacts was tested. The results are shown in Table 1.

[0073] Table 1 Performance test results

[0074] <![CDATA[Density g / cm 3 > Hardness (HB) MPa Electrical life test Molded AgCNi electrical contacts 8.2 75 2000 times AgCNi electrical contact according to the embodiment of the present invention 8.8 105 4000 times

[0075] For electrical contact materials, density and hardness reflect their density characteristics, and resistance to fusion welding is reflected by factors such as the electrical life, hardness, electrical conductivity, and thermal conductivity of the material, among which electrical life and hardness play a major role in resistance to fusion welding. According to the results in Table 1, compared with the existing AgCNi electrical contact material produced by the molding method, the AgCNi electrical contact material prepared in the embodiment of the present invention has a higher density, better resistance to fusion welding, and a longer electrical life.

[0076] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various modifications or variations within the scope of the claims, which does not affect the essence of the present invention. The above preferred features can be used in any combination without conflicting with each other.

Claims

1. A method for preparing an AgCNi electrical contact material, characterized in that: include: Mixing silver powder, nickel powder and graphite powder according to a preset ratio to obtain a mixed powder; The mixed powder is subjected to isostatic pressing to obtain an AgCNi ingot; Sintering the AgCNi ingot to obtain an AgCNi ingot; Extruding the AgCNi billet according to a preset deformation amount to obtain an AgCNi wire or strip; Decarburizing the AgCNi wire or strip to form an AgCNi wire or strip with four side walls all made of AgNiO; The decarburized AgCNi wire or strip is subjected to reduction treatment to obtain an AgCNi wire or strip with AgNi on four surfaces, namely, an AgCNi electrical contact material.

2. The method for preparing the AgCNi electrical contact material according to claim 1, characterized in that: The mixed powder is subjected to isostatic pressing to obtain an AgCNi ingot, wherein the pressure is 50MPa to 400MPa and the time is 10 seconds to 120 seconds.

3. The method for preparing the AgCNi electrical contact material according to claim 1, characterized in that: The sintering of the AgCNi ingot to obtain the AgCNi billet comprises: First, the AgCNi ingot is loaded into a sintering furnace and preheated in a protective atmosphere at a temperature of 200° C. to 500° C. for a preheating time of 0.1 hour to 3 hours; Then, the preheated AgCNi ingot is subjected to a second-stage sintering in a protective atmosphere, the sintering temperature is 350° C. to 650° C., and the sintering time is 0.5 hour to 5 hours; The third stage sintering is then carried out under a protective atmosphere, with a sintering temperature of 700°C to 950°C and a sintering time of 0.5 hour to 10 hours, and then the product is cooled to room temperature and taken out of the furnace.

4. The method for preparing the AgCNi electrical contact material according to claim 1, characterized in that: The AgCNi billet is extruded according to a preset deformation amount, wherein the preset deformation amount includes: an extrusion ratio of 20-300.

5. The method for preparing the AgCNi electrical contact material according to claim 1, characterized in that: The AgCNi ingot is extruded according to a preset deformation amount to obtain an AgCNi wire or strip, wherein: a hot extrusion method is adopted, the hot extrusion temperature is 500° C. to 900° C., and the extrusion time is 0.5 hour to 4 hours.

6. The method for preparing the AgCNi electrical contact material according to claim 1, characterized in that: The AgCNi wire or strip is subjected to decarburization treatment to form an AgCNi wire or strip whose four side walls are all AgNiO, wherein: the decarburization temperature is 600° C. to 850° C., and the gas flow rate is 5 to 20 L / min.

7. The method for preparing the AgCNi electrical contact material according to claim 1, characterized in that: The decarburized AgCNi wire or strip is subjected to reduction treatment to obtain an AgCNi wire or strip with AgNi on four surfaces, wherein the reduction temperature is 400° C. to 800° C. and the reduction time is 0.5 hour to 6 hours.

8. The method for preparing the AgCNi electrical contact material according to claim 1, characterized in that: Before subjecting the mixed powder to isostatic pressing to obtain the AgCNi ingot, the method includes: subjecting the mixed powder to ball milling.

9. An AgCNi electrical contact material, characterized in that: The method is prepared by any one of claims 1 to 8.

10. An electrical contact, characterized in that: Prepared by using the AgCNi electrical contact material according to claim 9, by cutting the AgCNi electrical contact material into pieces to obtain AgCNi particles with AgNi on all four surfaces; The AgNi layer on one side of the AgCNi particle is milled off to obtain a single-piece AgCNi electrical contact.

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